The XSetWMColormapWindows
function replaces the WM_COLORMAP_WINDOWS property on the specified window
with the list of windows specified by the colormap_windows argument. It
the property does not already exist, XSetWMColormapWindows sets the WM_COLORMAP_WINDOWS
property on the specified window to the list of windows specified by the
colormap_windows argument. The property is stored with a type of WINDOW
and a format of 32. If it cannot intern the WM_COLORMAP_WINDOWS atom, XSetWMColormapWindows
returns a zero status. Otherwise, it returns a nonzero status.

XSetWMColormapWindows
can generate BadAlloc and BadWindow errors.

The XGetWMColormapWindows
function returns the list of window identifiers stored in the WM_COLORMAP_WINDOWS
property on the specified window. These identifiers indicate the colormaps
that the window manager may need to install for this window. If the property
exists, is of type WINDOW, is of format 32, and the atom WM_COLORMAP_WINDOWS
can be interned, XGetWMColormapWindows sets the windows_return argument
to a list of window identifiers, sets the count_return argument to the
number of elements in the list, and returns a nonzero status. Otherwise,
it sets neither of the return arguments and returns a zero status. To release
the list of window identifiers, use XFree.